1. Field of the Invention
The present invention relates to an image capturing device having a hand shake correction function, a hand shake correction method, and a storage medium storing a hand shake correction process program, and more particularly, to an image capturing device having a hand shake correction function, a hand shake correction method, and a storage medium storing a hand shake correction process program, which can make a correction with higher precision.
2. Description of the Related Art
If shooting is made with a digital camera (image capturing device) built in a cellular phone, etc., an influence of a hand shake is exerted on an image to be captured, for example, due to a reason that a hand holding the cellular phone shakes during an exposure time. To suppress the influence exerted by the hand shake, a hand shake correction is made to the captured image.
In recent years, a digital camera, especially, a digital camera included in a cellular phone has rapidly become widespread. Additionally, a user demand for the performance and the convenience of a digital camera has been increasing.
In response to such a demand, not only increases in pixilation and a zoom factor in terms of performance but also reductions in size and weight in terms of convenience have been in rapid progress.
However, such improvements in the performance and the convenience can cause a hand shake to easily occur. Especially, a digital camera built in a cellular phone is carried all the time, and accordingly, shooting is made, for example, in a very dark place in many cases. However, since a flash is not built in most cases, a hand shake tends to occur in comparison with other digital cameras.
As methods for coping with a hand shake, a method for optically correcting a hand shake, and a method for correcting a hand shake with a digital process are conventionally proposed.
For a normal digital camera, a method for optically correcting a hand shake has already been commercialized. Meanwhile, for a digital camera built in a cellular phone, a method for correcting a hand shake with a digital process has started to be commercialized.
With a camera adopting a method for correcting a hand shake with a digital process, one image to which a hand shake correction is made is obtained by superimposing a plurality of images captured with continuous shooting. Such a hand shake correction method fixes an image, which becomes a base used when images are superimposed. Therefore, it becomes impossible to correct a shake that occurs in the base image, and the amount of shake appears as the amount of shake of a corrected image. For example, if n images are shot with continuous shooting, the images are synthesized by fixedly regarding an mth (1≦m≦n) image as a base image among the 1st to the nth images. If a shake that occurs in the mth image is big at this time, a similar shake is left also in a corrected image. Therefore, an expected correction effect cannot be obtained.
Furthermore, as other techniques for correcting a hand shake, for example, techniques disclosed by Patent Documents 1 and 2 are known.
Patent Document 1 discloses an electronic camera having, two modes such as a shake correction mode and a non-shake correction mode. With this electronic camera, a shake correction is made in each exposure period of a CCD during a shooting preparation period (in the non-shake correction mode), and the shake correction is not made while pixel data is output.
Patent Document 2 discloses a camera that can control the operation speeds of a mirror and a shutter by changing from the speeds in a normal shooting mode, when an anti-shake shooting mode is selected. A shooting mode selecting unit of this camera selects the shooting modes of the camera, such as the anti-shake shooting mode, the normal shooting mode, etc. Additionally, a driving speed changing unit outputs, to a mirror driving unit and a shutter driving unit, an instruction to change the driving speeds of the mirror and the shutter when exposure is started based on a result of the selection made by the shooting mode selecting unit.
[Patent Document 1] Japanese Published Patent Application No. 2003-333414 “Electronic Camera”
[Patent Document 2] Japanese Published Patent Application No. H7-28149 “Camera Shake Preventing Device”